We have based our hat measurements below on an average size head for these ages. However childrens head sizes vary a lot! Some are on the smaller side, some average and some on the larger size (like my 98th% head circumference son!).
Use a measuring tape, piece of string or jute to wrap around your childs head. Place it around the forehead, above the ears and around the largest part at the back. We recommend taking three measurements and use the largest measurement.
If in doubt and/or your child's head is close to the maximum measurement, we recommend going up a size. There are studs at the back of the hat so you can tighten it up if needed.
Please note: Mille in zest has a little bit of extra room in it due to the super soft drape and construction of the fabric.